Natural gas and other fluids may be transported, distributed, and/or sold to customers through a system of transmission and distribution lines. For purposes such as billing and inventory control, for example, gas metering systems may be installed at various locations along these gas lines. Gas metering systems may measure the volume of gas that flows through a particular gas line. Some gas metering systems include a gas meter and an electronic or mechanical volume corrector.
One type of gas meter is a rotary gas meter. In some rotary gas meters, gas flowing through the meter causes a set of impellers to rotate within a cylinder. Each impeller rotation indicates that a certain volume of gas has flowed through the meter. In general, the performance of a meter is unlikely to improve over time, as bearings and gear system in the gas meter become worn or contaminated. As the bearings or timing gears wear due to friction, it is possible that the volume measurement accuracy of a rotary flow type meter will degrade. To combat this degradation in performance and extend the life of the meter, bearings, gears, and other mechanical components are generally exposed to a lubrication oil bath within the meter. The oil fluid in the lubrication oil bath may be sealed in a compartment that is internal to the gas flow meter body. The oil can lubricate the various mechanical parts of the meter such as the timing gears and the bearings. Such a configuration, however, normally requires the oil to be exchanged from the sealed compartment or otherwise requires the lubricant oil bath compartment to be periodically serviced. In a gas flow system that includes a large number of gas meters, the service and repair of the lubricant oil bath compartments in the gas flow meters can be time consuming.